A25 re-power/shaft and prop issues

[WillieC]

Hi, all you A25 engine upgraders

I have an earlier post about A25 propellers and cutlass. My boat is a 1973 Deluxe, I guess, with the stock Volvo Penta MD3B, RB transmission.

I am seeing a number of Yanmar, Kubota, Westerbeke, VW engine swaps and surely you all have had to deal with new propellers to match the new engine to the boat and surely you all have had to deal with the fact that finding a 25 or 30 mm propeller in 'Merica is challenging at best. And while you were at it, you surely had to deal with the funky self-centering oddball size cutlass bearing...

The best solution I am coming up with is swapping the shaft out for 1-1/8", buy a readily available SAE prop. Which would include a new PSS type shaft seal, modifying the coupler at the transmission, but you still have to deal with that cutlass bearing.

I am pretty confident I can get the original 30mm cutlass from Albinmotor in Sweden, though I haven't heard back from them regarding availability. How have y'all solved this little conundrum? Do I keep the 30mm shaft (or start with a new one, which I am sure is just about as available as a metric prop) and have the prop end machined for the SAE prop? Or go with a new 1-1/4" shaft and machine both ends down to 30mm for the cutlass that fits the boat and the pss and tranny coupler or haul the boat out into the canal and scuttle it? I know I am not the first one to ponder these things.

I have found a Jeanneau Beneteau Prop Shaft Bearing 30 x 40 x 120mm that, except for excess length (I have a saw), could possibly be adapted for replacing the stock A25 cutlass. The whole thing is non metallic and one would have to figure a way to hold it in place and still be somewhat self-centering, like the original. Your standard bronze 30mm cutlass has a 45 mm outer dimension, too big for the A25.

Just curious how all you engine swappers solved these problems. I am not quite ready to pull that trigger yet. This old MD3B still runs too good.

All your comments have been very helpful. Thank you.

[Northern Spy]

Mine was repowered by the previous owner with a Universal 5424 (25hp) diesel engine. The prop shaft was machined down to 1" and a SAE prop was used. I don't know the details about the coupler, but a PSS shaft seal was used. I ordered a stock 30mm cutlass bearing from albinmotor last month and had no problems. Just select the part and use PayPal. It arrived in less time than most domestic parts orders!

[kerrye]

I bought some curtain rod holders from Albinmotor a few weeks ago. They came very quickly. However, there was something funky when it came to paying with Paypal. I chose Paypal but the order never actually went through. A few days later, I contacted them and it turned out they needed to send me an invoice via Paypal which I then paid. So confirm your order with an e-mail to them if something seems odd with the Paypal part.

My boat was repowered with an Westerbeke 42. It still has the original stuffing box so I assume it still has the original shaft. Don't know about the prop.

Personally, I'd go with the British prop supplier mentioned in your other thread. Seemed like a good price.

[WillieC]

Thank you, both for great answers. Tacoma prop was suggesting 1-1/8" shaft machining, but I don't think there is enough material for that, but for 1", yes! Makes sense. Leave the rest of the shaft at 30mm and that works for the rest of the parts. I imagine that 36 hp isn't going to twist a 1" shaft. The rest of the boat is overbuilt as well.
Curious why I haven't heard back from Albinmotor, so I will try to reconnect with them.
The British prop does look like the way to go for the quickest solution. Will have to figure out my taper, I think it is 1/10 from my rudimentary measurements. Can anybody else weigh in on that? Are there any 1/12 Albin shafts out there? I can't imagine that they switched back and forth through the years.

I guess I'll postpone my plan to scuttle the boat just yet. I'll start with the cutlass. Keep scrounging for a used prop, since this one should last one more season. Try to find a machine shop to look at the tranny, and then decide where to go next. Swapping the engine with the MD17C spare will no doubt entail shaft work so I can do that work then.

You folks are great. Thank you for your assistance. ra WillieC

[denchen]

Just to let you know my A25 has a straight through 1 inch shaft on a 37 hp 4 cyl diesel through a 1;2.05 reduction gearbox driving a 16 *14 inch 3 blade prop on a 1;12 taper and 1/4 inch key. I didnt work out the taper, I just sent the shaft size, the thickness of the prob boss and the size of the small end hole to Norris`s and they worked it out and machined my new prop on ordering. It fitted a treat and has been no problems

[Tree]

Just skimming through this thread and I would think you'll have no issue with a 1" shaft running that sort of power. Bear in mind on the 28's we are running 1.5" shafts with 300hp running through them and that shaft is 8' long. If you wanted to increase the hp of the engine and maintain the shaft diameter, have a look into having a new shaft made for duplex or if you're going over kill super duplex. I'm sure you will have no issues at all.

[Tree]

Denchen, can I recommend Clements Marine to you. They made my new propeller last year for the 28 and with no engine change or gearbox change they've managed to squeeze another 2 knots at full rpm and an extra 1.5 at cruise with the technology they're using.

[denchen]

Thank Tree, but the set up I have now seems to be working fine. My 1 inch shaft was in when I got the boat and I`ve no history on it, so do not to push it too much. If for some reason I have need to change the shaft I will be looking at the stronger stainless as I don`t like the thin 1 inch.

[WillieC]

Just pulled the shaft on the 1973 A25. Fortunately, somebody else has been here in the last decade, because it actually came apart without flame and much profanity.
AND I found another shaft bearing at the inboard side of the shaft tube. It is as wobbly as the cutlass, and I am fairly certain, the combination of the two is the cause of all the racket. I was going down the road of noisy transmission bearings, so I thought i would isolate it all and see what's up. I can't believe it all came apart, especially the shaft coupler pinched and keyed onto the end of the shaft.
So now I have to figure out this issue.
Way back last year, I posted either to this site or BC Albineers, and someone suggested that this shaft is too long for only a cutlass bearing. He was correct. But whatever intermediate bearing is used ought to actually fit the shaft. Both of my bearings are sporting about 1/8" gap. No wonder there is such a harmonic racket in the cabin.
I see Albinmotor lists an inner bearing, it probably went with the original stuffing box. It looks more like a bushing, which likely will not work well with the PSS shaft seal that is currently installed. Though, I suppose the excess water pressure would simply back up into the raw water cooled exhaust. What I really need is a cutlass style grooved bearing that will let the water flow.
And this may be where the Jeauneau Beneteau non-metallic bearing may be adapted, as it has a 40mm outer dimension, rather than the stand 45mm bronze cutlasses readily available. The 40 mm is fairly close to the tube inner dimension. Cant' tell until I remove the upper plastic bearing/bushing/sleeve. Wish me luck!

Will keep you posted.

[kerrye]

Any pictures of the inner bearing?

[DesertAlbin736]

I'm afraid I won't be much help here, but I inherited a Yanmar 3GM30F with Aqua Drive CV joint unit and thrust bearing. That I guess takes care of any problems with a forward cutlass bearing. Probably the main issue besides metric vs SAE shaft and bearings with going from Volvo to some other make engine is the fact that Volvos have left hand props, and everyone else is right hand so you'd have to replace the prop anyway. I don't know if there's a 2nd inboard shaft bearing on mine or ever was, but the packing gland is attached via a flexible rubber hose & hose clamps and has some give. I guess whatever minor shaft alignment irregularities there may be are are taken care of by the CV joint. Anyway, one would think a 1" shaft could somehow be machined down to 25 mm where needed, or reaming a 1" bearing out to 25mm since 1 inch = 25.4 mm, so we're only talking about .016 inches difference. I'm just glad I don't have to deal with these issues myself but would like to hear how it turns out.

[kerrye]

Have you read this account of an A25 cutlass bearing problem and its solution?

http://msbettencourtsnewtop.blogspot.co ... comes.html

[WillieC]

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Here are some pics.

Kerrye, yes I did read Ms. Bettencourt's story. His picture is of a stock (non-Albin, at least not my Albin) cutlass bearing, the metrics being 30mm inside and 45 mm outside. Now that I have mine all apart, I find that the shaft tube is 40mm give or take depending which glob of rust or sealife or corrosion you measure. Take an average it's 40mm. I think I can make the beneteau non-metallic bearing work on both ends. It comes with a flange, very similar to the existing white plastic bearing I just removed from the inside. I wanted to remove it in one piece, so I could replace it if I couldn't come up with a fix. I tried a heat gun on the tube, Calcium, Lime, Rust remover at the joint and 4" channel locks exerting judicious torque (thus the serrations shown in the pictures). Nada. Went inside for lunch and a brew trying to devise some kind of puller in my head. A piece of 1/2" threaded rod and a 1-1/8" half-inch drive socket that just fits inside the tube. My plan was to rig up the inside-the-boat end with some blocks and an end board with a hole in it. Classic homemade puller. Don't know if it was the beer break, CLR, or heat that did the trick, but I was able to fish the socket/threaded rod combination up the shaft tube and use it as a sort of slide hammer against the inside end of the upper bearing and viola! Out it came! Think dent puller for body repair. This was a good day!
Now if I can just find these bearings. ASAP supply has them, again across the pond, and I don't know anything about them. And the same part has two prices on the same page, substantially different. Both include VAT. Huh? I have a request out to a supplier back east, seems like somebody ought to have these things stateside. The big houses, Duramax and another I forget show their NonMetallic bearings with the same dimensions as the brass sleeved ones, i.e. 45mm outside. And no flange.
Note in the pictures that the upper bearing has no grooves like your common stave bearing. More like a plastic bushing. Just inside of that (toward the engine) is my PSS shaft seal. The only way water got through that in sufficient quantity is the fact that it was an eighth inch loose. So slotted new bearing is the way to go. Note also that there was some kind of glue or epoxy holding the whole thing in place. I suppose I will do the same or drill and tap a screw into the hole provided in the new bearing (if I can find them).
The bottom end will take the flange nicely AND I will use the old worn Albin funky bearing to hold it all in place. The flange will push everything toward the prop the thickness of the flange, which I will probably compensate for by shortening the original bearing the same difference. I need that room for the zinc, and axial movement of the shaft.
Now if I can just find those bearings 30mm x 40mm x 120mm, non metallic, with flange.
One more item. Note how short both of the original bearing surfaces are. 1-3/4" upper and 2-3/4" lower. If I can use the beneteau style bearing both go up to 4-3/4" (120mm) which has got to wear better and keep things nicely aligned. Oh, and cut down the racket.

[denchen]

ASAP are a good company that give fast service. I have used them many times over many years, they know what they are doing. VAT is `value added tax`, that is 20% on most goods we have to pay in the UK. For you guys across the pond it should be tax free so less the 20%.

[WillieC]

Thanks Denchen, this is good to hear. I now have three prices for the same part. Waiting for them to sort it out.